Abstract: A personal portable terminal includes a transmitter that transmits a position determination signal to be used for position determination to a position determination device, and a controller that controls the transmitter. The position determination apparatus includes a plurality of first and second receivers that are arranged at different first and second positions which are spaced at first and second distances away from the personal portable terminal, respectively, to receive the position determination signal transmitted by the transmitter, and a calculator that determines the position of the personal portable terminal based on a difference between an intensity of the position determination signal that is received by the first receivers and an intensity of the position determination signal that is received by the second receivers. The second distance is greater than the first distance.

Abstract: An authentication-gaining apparatus includes: an acquiring unit that acquires unique information; an encrypting unit that encrypts the unique information using a cryptographic key, thereby generating encrypted information; and a transmitting unit that repeatedly transmits an authentication request containing the encrypted information, to an authentication apparatus, during an authentication period, wherein multiple authentication requests respectively containing encrypted information obtained by encrypting multiple pieces of unique information are transmitted during the authentication period.